A prefilled syringe or a vial filled with a pharmaceutical product in advance has been manufactured for convenience at medical fields. A work of filling these syringes and vials with pharmaceutical products is conducted in a filling workroom in an aseptic environment (hereinafter referred to as an aseptic workroom).
A product container such as a syringe and a vial used in this work is small in size but the quantity to be processed is large and can be continuously conveyed into the aseptic workroom from outside the workroom. At that time, in order to ensure the aseptic state of the syringe or the vial, they are conveyed into the aseptic workroom inline through a continuous sterilization system.
Sterilization means used in these continuous sterilization systems includes dry and high-temperature hot air, hydrogen peroxide gas, EOG (ethylene oxide gas), electron beam irradiation, Gamma(γ)-ray irradiation and the like. Among them, as a method capable of processing at a low temperature and leaving no remaining residues in articles to be sterilized and which is safe and easy to be handled, a method using a low-energy electron beam has been widely employed.
Moreover, the product containers such as syringes and vials need to be sterilized not only on an outer surface but also an opening portion to a portion on an inner surface in which a drug is to be filled. However, when these small product containers are continuously conveyed in the continuous sterilization system, there is a problem that the electron beam is not emitted to a portion in contact with a conveying member such as a conveyer or a lift and this portion is not sterilized.
Thus, in the following Patent Literature 1, as an electron-beam irradiation continuous sterilization system for performing electron beam irradiation from a vertical direction while the product container is being conveyed by a mesh conveyer, employment of a slide guide is proposed.
According to this method, the product container having been conveyed by the mesh conveyer in its traveling direction slides and moves on the mesh conveyer in a diagonally lateral direction along the slide guide. As a result, a position where a bottom surface of the product container and a mesh of the mesh conveyer are in contact with each other changes, and the electron beam emitted from below through the mesh conveyer irradiates the entire bottom surface of the product container.